xref: /linux/Documentation/devicetree/bindings/access-controllers/access-controllers.yaml (revision 429508c84d95811dd1300181dfe84743caff9a38) 
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/access-controllers/access-controllers.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Generic Domain Access Controllers
8
9maintainers:
10  - Oleksii Moisieiev <oleksii_moisieiev@epam.com>
11
12description: |+
13  Common access controllers properties
14
15  Access controllers are in charge of stating which of the hardware blocks under
16  their responsibility (their domain) can be accesssed by which compartment. A
17  compartment can be a cluster of CPUs (or coprocessors), a range of addresses
18  or a group of hardware blocks. An access controller's domain is the set of
19  resources covered by the access controller.
20
21  This device tree binding can be used to bind devices to their access
22  controller provided by access-controllers property. In this case, the device
23  is a consumer and the access controller is the provider.
24
25  An access controller can be represented by any node in the device tree and
26  can provide one or more configuration parameters, needed to control parameters
27  of the consumer device. A consumer node can refer to the provider by phandle
28  and a set of phandle arguments, specified by '#access-controller-cells'
29  property in the access controller node.
30
31  Access controllers are typically used to set/read the permissions of a
32  hardware block and grant access to it. Any of which depends on the access
33  controller. The capabilities of each access controller are defined by the
34  binding of the access controller device.
35
36  Each node can be a consumer for the several access controllers.
37
38# always select the core schema
39select: true
40
41properties:
42  "#access-controller-cells":
43    description:
44      Number of cells in an access-controllers specifier;
45      Can be any value as specified by device tree binding documentation
46      of a particular provider. The node is an access controller.
47
48  access-controller-names:
49    $ref: /schemas/types.yaml#/definitions/string-array
50    description:
51      A list of access-controllers names, sorted in the same order as
52      access-controllers entries. Consumer drivers will use
53      access-controller-names to match with existing access-controllers entries.
54
55  access-controllers:
56    $ref: /schemas/types.yaml#/definitions/phandle-array
57    description:
58      A list of access controller specifiers, as defined by the
59      bindings of the access-controllers provider.
60
61additionalProperties: true
62
63examples:
64  - |
65    clock_controller: access-controllers@50000 {
66        reg = <0x50000 0x400>;
67        #access-controller-cells = <2>;
68    };
69
70    bus_controller: bus@60000 {
71        reg = <0x60000 0x10000>;
72        #address-cells = <1>;
73        #size-cells = <1>;
74        ranges;
75        #access-controller-cells = <3>;
76
77        uart4: serial@60100 {
78            reg = <0x60100 0x400>;
79            clocks = <&clk_serial>;
80            access-controllers = <&clock_controller 1 2>,
81                                 <&bus_controller 1 3 5>;
82            access-controller-names = "clock", "bus";
83        };
84    };
85